We have previously described the syndrome of winter seasonal affective disorder (SAD), which is characterized by symptoms of depression that recur regularly during the fall and winter months and remit in spring and summer. Although the clinical picture of SAD has been well delineated, little research has been done on its longitudinal course. The condition has been described predominantly in adults, though we and others have reported on a relatively small number of children and adolescents with SAD. While SAD patients are generally considered to be highly sensitive to changes in their physical environment, most notably decreased environmental light the possible pathogenic role of psychological stressors has been less well explored. A follow-up study of 23 adult patients, discharged from our clinic on average 6 years ago revealed that 16 (70%) patients remained "exclusively seasonal". Thirteen (57%) continued to use light therapy regularly and successfully each winter after an average of eight years since the diagnosis of SAD had been made. All patients continued to experience worsening of their moods during the winter months, most often in February, and all continued to endorse, and remain invested in, the construct of SAD. Phone interviews with six of the seven children and adolescents with SAD previously studied indicated that all continued to experience some form of seasonal dysfunction, although knowledge about the condition has enabled them to deal effectively with the winter. Five had light boxes in their homes, which they used in an "as needed" and unstructured manner. All reported making conscientious efforts to spend time outdoors during the winter and developed outdoor hobbies. Two reported great benefit from fluoxetine. Patterns of symptomatology for individual cases remained quite stable over time. Evaluation of stress, cognitive appraisal and coping in 37 SAD patients revealed that depressive episodes in SAD patients were not generally precipitated by major life events. SAD patients reported more frequent and severe minor daily stressors than 29 normal controls during the winter when they were depressed. SAD patients did not differ from controls or across seasons in their evaluation of the significance of stressful events or their perception of available resources and coping options. When they were depressed, however, SAD patients did use coping strategies typical of depressives in general, namely those involving more avoidance, regulation or discharge of affect and less problem solving.